966 resultados para Cut thickness
Resumo:
Pós-graduação em Cirurgia Veterinária - FCAV
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
ABSTRACT The aim of the present study was to analyze the influence of enriched environment on the distribution of perineuronal nets (PNNs) using a stereogically based unbiased protocol and visual acuity in adult Swiss albino mice that underwent monocular deprivation during the critical period of postnatal development. Eight female Swiss albino mice were monocular deprived were removed and cut at 70 µm thickness in a vibratome and processed for lectin histochemical staining with Wisteria floribunda agglutinin (WFA). Architectonic limits of area 17 were conspicuously defined by WFA histochemical staining, and the optical fractionator stereological method was applied to estimate the total number of PNNs in the supragranular, granular, and infragranular layers. All groups were compared using Student's t-test at a 95% confidence level. Comparative analysis of the average PNN estimations revealed that the EE group had higher PNNs in the supragranular layer (2726.33 ± 405.416, mean ± standard deviation) compared with the SE group (1543.535 ± 260.686; Student's t-test, p = .0495). No differences were found in the other layers. Visual acuity was significantly lower in the SE group (0.55 cycles/degree) than in the EE group (1.06 cycles/degree). Our results suggest that the integrity of the specialized extracellular matrix PNNs of the supragranular layer may be essential for normal visual acuity development.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Utilizando-se dados do campo de Camorim (Bacia de Sergipe-Alagoas), foi testado e aplicado um conjunto de técnicas estatísticas multivariantes (análises de agrupamentos, de componentes principais e discriminante) no intuito de identificar as fácies, previamente definidas em poços testemunhados, por meio dos perfis, viabilizando o reconhecimento das mesmas nos demais poços não testemunhados da área. A segunda etapa do processo de determinação das fácies consistiu no emprego de métodos auxiliares (análises composicional e de seqüência de fácies), que, combinados com as técnicas multivariantes, propiciaram melhores resultados na calibração rocha-perfil. A determinação das fácies, uma vez estabelecida, possibilitou o refinamento do processo de avaliação de formações ao viabilizar o exame de cada fácies-reservatório, isoladamente. Assim, esse procedimento tornou possível a escolha, para cada litologia, dos parâmetros utilizados na interpretação dos perfis ao mesmo tempo em que permitiu a totalização em separado dos valores de espessura, porosidade e saturação dos fluidos, bem como a adoção de diferentes valores de corte (cut-offs) para cada grupo considerado. Outras aplicações incluíram a melhoria na estimativa da porosidade e da permeabilidade, a adaptação de algoritmos para o cálculo preliminar de porosidade, a confecção de mapas de fácies e a geração automática de seções estratigráficas. Finalmente, foram destacadas a perspectiva de integração desse estudo com sistemas estatísticos de descrição de reservatórios, outras técnicas de determinação de fácies em desenvolvimento e a retomada da utilização de métodos estatísticos multivariantes em dados de perfis, como ferramenta de exploração.
Resumo:
To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37) on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively). Three cells (4.5%) were bistratified, having thick dendrites, and the others (95.5%) were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40%) and 2 groups with inner (50-100%) stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.
Resumo:
The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the “risk zone” of mandibular molars. Objectives: The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated. Material and Methods: Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student’s t-test was used to determine significant differences at p<0.05. Results: No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness. Conclusion: Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars.
Resumo:
Pós-graduação em Matemática - IBILCE
Resumo:
Examining three bleaching systems, this in vivo clinical trial evaluated the relationship among tooth sensitivity, light activation, and agent concentration, and it correlated dental sensitivity with tooth thickness.Materials and Methods: Eighty-seven volunteer patients were included. Inclusion criteria were the presence of anterior teeth without restorations as well as the absence of a previous bleaching experience and absence of non-carious cervical lesions or dental pain. Exclusion criteria included pregnancy or breastfeeding, a maximum of TF3 hypoplasia, tetracycline-fluorosis stains, malpositioned teeth, orthodontic treatment, periodontal disease, and/or analgesic/anti-inflammatory intake. Patients were randomly assigned to three bleaching groups: Group A (n=25) was treated with 15% H2O2 and nitrogenous-titanium-dioxide and was light activated (Lase Peroxide Lite, DMC, SaoCarlos, Sao Paulo, Brazil); Group B (n=27) was treated with 35% H2O2 and was light activated (Lase Peroxide Sensy, DMC); and Group C (n=35) was treated with 35% H2O2 (White Gold Office, Dentsply, 38West Clark Ave., Milford, USA) without light activation. Tooth sensitivity (TS) was self-reported by the patients using the visual analog scale (VAS) at baseline (TSO), immediately after treatment (TSI), and at seven days after treatment (TS7). In 46 patients, tooth thickness was determined by computed tomography. TSO, TSI, and TS7 were compared between the A and B groups to determine the effect of concentration and between the B and C groups to determine the effect of light using analysis of covariance. The correlation between tooth thickness and TSI was determined by Spearman Rho test (SPSS 15).Results: Eighty-seven patients were evaluated at baseline, and 61 were evaluated at seven days. Separated by groups, tooth sensitivity, expressed as VAS value at the time points TS0, TS1, and TS7, respectively, were as follows: Group A: 13.76 +/- 13.53, 24.40 +/- 25.24, and 5.94 +/- 5.5; Group B: 15.07 +/- 18.14, 42.4 +/- 31.78, and 8.68 +/- 17.99; and Group C: 10.80 +/- 14.83, 31.51 +/- 29.34, and 7.24 +/- 9.2. Group A showed significantly lower tooth sensitivity than group B at TSI (p=0.032). No differences were observed in the tooth sensitivities between groups B and C. No correlation was encountered between tooth thickness and tooth sensitivity immediately after treatment (Rho=-0.088,p=0.563). The median tooth thickness was 2.78 +/- 0.21 mm.Conclusions: Increases in the concentration of bleaching agents directly affect tooth sensitivity, and LED/laser activation and tooth thickness are not correlated with tooth sensitivity after dental bleaching.
Resumo:
Adhesive restorations have increasingly been used in dentistry, and the adhesive system application technique may determine the success of the restorative procedure. The aim of this study was to evaluate the influence of the application technique of two adhesive systems (Clearfil SE Bond and Adper Scotchbond MultiPurpose) on the bond strength and adhesive layer of composite resin restorations. Eight human third molars were selected and prepared with Class I occlusal cavities. The teeth were restored with composite using various application techniques for both adhesives, according to the following groups (n = 10): group 1 (control), systems were applied and adhesive was immediately light activated for 20 seconds without removing excesses; group 2, excess adhesive was removed with a gentle jet of air for 5 seconds; group 3, excess was removed with a dry microbrush-type device; and group 4, a gentle jet of air was applied after the microbrush and then light activation was performed. After this, the teeth were submitted to microtensile testing. For the two systems tested, no statistical differences were observed between groups 1 and 2. Groups 3 and 4 presented higher bond strength values compared with the other studied groups, allowing the conclusion that excess adhesive removal with a dry micro-brush could improve bond strength in composite restorations. Predominance of adhesive fracture and thicker adhesive layer were observed via scanning electron microscopy (SEM) in groups 1 and 2. For groups 3 and 4, a mixed failure pattern and thinner adhesive layer were verified. Clinicians should be aware that excess adhesive may negatively affect bond strength, whereas a thin, uniform adhesive layer appears to be favorable. (Quintessence Int 2013;44:9-15)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)